Help is just a click away!
Click here to chat with a Speedway Team Member
Online - Chat with us!
Products to Compare (max of 3)
Compare These Parts
Talk to the Experts. Call 800.979.0122, 7am-10pm, everyday.
Customer Service
Since 1952
Talk to the Experts. Call 800.979.0122
Shop By
Street Race Truck More... The Toolbox

How to Build 4-Link Bars


Since not all applications will have a kit available, Speedway Motors sells the parts needed to build your own 4-link bars. My project truck is one of those applications where I would have to do some fabrication to get exactly what I wanted. Here’s a guide to help you if you ever need to build your own links of any kind.

How to Determine Cut Length For 4-Link Tubes:

The general rule is that you must have at least as much thread inside the tube as the diameter of the threads. So in my case using 3/4-16 rod ends, I must have at least 3/4” of an inch threaded inside to remain safe.

When building your 4-link bars (or any other type of adjustable links) you want to have them in the middle of the adjustment range so you can have enough adjustment to set up your suspension. My goal is to end up with 31.75” center to center length 4-links, in the middle of the adjustment range.

Here’s the math I used to figure out the tube cut length:

(3/4-16 Threaded 4-Link Rod End has 1.950” threaded length)

1.950” total threaded length - .750” minimum threaded into tube - .4375” thick jam nut = .7625” is the maximum thread sticking out from the jam nut allowed, and still have .750” threaded inside the tube

.7625”/2 = .3812” is the middle of the adjustment range

Here you can see the finished 4-link bar with the rod end adjusted to the middle of the allowable stick out.

With the rod end and jam nut adjusted to the middle of the adjustment range, measure the center of the hole to the end of the weld bung, and I got 2.650”. I will add .100” of gap between the weld bung and the tube when I weld to get good penetration, so this measurement ends up being 2.750”.

2.750” x 2 = 5.50” 31.75” center to center 4-link length -5.50” =26.25” cut length for the tube

Weld & Assemble Links

After I cut the 1.375” o.d. X .1875” wall 1026 DOM steel tube I used for these links, it was almost time to weld them up. Before welding, I chamfered the ends of the tube to allow for good weld penetration, and I also like to drill a couple of holes so I can also rosette weld the sides of the weld bung. I used a 3/8” step drill bit to drill through both sides of the tubing.

After drilling the holes, there was a little burr left from the drill bit. I used a small 3/4” flap wheel sander to clean up the inside of the tubing.

The weld bung slides nicely into the 1.0” i.d. tubing. At this point, the links are ready to be welded.

After TIG welding the bungs to the tube, I used my grinder to level the welds and then used a dual action sander with 120 grit to smooth the tubes out.

With my 4-link bars all welded up, I am finally ready to get my rear suspension setup and in place.

Products Featured in this Article

Related Articles

Trying to Cut Carbs?
by Heath Petzoldt - Posted in Tech
Do you have carbs sitting on the shelf waiting to be put on? Heath talks about the preparation and parts needed to install a set of Super 9-7 Carbs on his 1949 Flathead 8BA V8 Model A.
Upgrading Your Air Cleaner Assembly
Learn the proper steps in upgrading your air cleaner assembly to ensure clean air, allowing your engine to more easily make the power that it should.
Take a Kid to a Car Show
by Jeff Karls - Posted in Street Rod
What is it like growing up going to car shows? This story explains how attending car shows is a way of life and how the tradition is passed on from generation to generation.
Ignition Upgrades for Classic Mopar Muscle
by Tyler Wesely - Posted in Street Rod
Bringing an old Mopar back to life isn't always a breeze. Fortunately, MSD has come up with a solution for those outdated and unreliable points-type ignition systems. Find out how to install a MSD 8386 distributor and MSD 5531 spark plug wires
Installing Radiator Support Rods
by Heath Petzoldt - Posted in Tech
We all need a little help from time to time. In this case, we had a grill shell on a 1946 Chevrolet Truck that could use some stiffening. Ride along as Heath installs support rods and rod brackets.
Car Show Planning 101
by Heath Petzoldt - Posted in Tech
Do you have the 'car bug' and love to attend car shows or racing events? This article gives an overview of what all goes into planning a show and tips on how to get started.
Installing Insulation & Loop Carpet on a Car Floor
by Darrian Wedding - Posted in Tech
Learn how to install insulation and loop carpet on a car floor to improve the appearance, reduce noise and heat impact, and enjoy driving your car even more.
Keeping your 1955 Chevy Cool
by Zach Raddatz - Posted in Tech
Shortcuts don't always pay off. Zach Raddatz walk us through his experience with a cheap radiator so we don't make the same mistake!
'32 Ford Hot Rod
by Joe McCollough - Posted in Tech
Look up "hot rod" in the dictionary and you'll see a picture of this car.
Project Chevelle LS Swap Tech Article
by Joe McCollough - Posted in Tech
Curious about LS swapping your muscle car? In this article, we'll discuss how we built up a 500-horse 6.0 and stuffed it in our Project Chevelle!